Chem 2

• Gravimetric analysis


  Analysis based on the measurement of mass
• Precipitation method


  • A method of gravimetric analysis
• Volatilization methods


  • Methods of gravimetric analysis
• Titrimetric analysis


  Analysis based on the measurement of volume
• Acid/base titrations


  • A type of titrimetric analysis
• Back titrations in acid/base titrimetric analysis


  • A technique used in acid/base titrations
• Titrations monitored by measurement of pH (potentiometric titrations)


  • A type of titrimetric analysis
• Thermometric and conductimetric titrations


  • Types of titrimetric analysis
• Primary standards


  Substances used to standardize titrants
• Redox titrations


  • A type of titrimetric analysis
• Spectroscopy


  The study of the interaction of electromagnetic radiation with matter
• Electromagnetic radiation


  Energy transmitted through space in the form of waves
• Regions of the electromagnetic spectrum


  • Radio
  • Microwave
  • Infrared
  • Visible
  • Ultraviolet
  • X-ray
  • Gamma ray
• Interaction of electromagnetic radiation with atoms and molecules


  Absorption, emission, and scattering of radiation
• Ultraviolet–visible spectroscopy


  Spectroscopy using ultraviolet and visible light
• Molecular orbitals in covalent molecules


  Discrete energy levels that electrons occupy
• Absorption of energy by electrons in molecular orbitals


  Electrons can absorb energy and transition to higher energy levels
• Studying absorption of UV–visible radiation


  Measuring the amount of light absorbed by a sample
• Infrared spectroscopy


  Spectroscopy using infrared radiation
• How organic molecules absorb infrared radiation

  Absorption causes vibrational and rotational transitions in molecules
• Interpreting infrared spectra


  Identifying functional groups and molecular structure from absorption peaks
• Mass spectrometry


  Technique that measures the mass-to-charge ratio of ions
• How mass spectra are obtained


  Ionization, separation, and detection of ions
• Phase separations


  Techniques that separate mixtures based on differences in physical properties
• Simple distillation


  • Separates liquids based on differences in boiling points
• Fractional distillation


  • Separates complex mixtures of liquids based on differences in boiling points
• Vacuum distillation


  • Distillation carried out under reduced pressure
• Steam distillation


  • Distillation using steam to volatilize components
• Solvent extraction


  • Separates compounds based on differences in solubility
• Chromatography


  Technique that separates mixtures based on differences in partitioning between mobile and stationary phases
• Elution


  The process of components being carried through the stationary phase by the mobile phase
• Locating individual substances


  Detecting the presence and amount of components in a mixture
• Ion-exchange chromatography


  • Separates ions based on differences in affinity for ion-exchange resin
• Identifying peaks in a chromatogram


  Relating peaks to the presence and amount of individual components
• Gas-liquid chromatography


  • Separates volatile compounds based on differences in boiling points and interactions with stationary phase
• The atmosphere


  • Environmental effects of industrial activities on the atmosphere
• Covalent bond


  Formed from one electron provided by C and one electron provided by H
• Covalent bonds in alkanes


  • Electrons in each bond are paired and have opposite spins
  • Negatively charged electrons provide the force that holds the positively charged atomic nuclei together
  • Electron pairs in one bond repel the electrons in a neighbouring bond
  • This leads to a three-dimensional arrangement with angles of 109.5° between any two of the bonds
• Methane, CH4


  Simplest hydrocarbon, containing carbon and hydrogen only
• Forming ethane, H3C-CH3


  1. Join two carbon atoms together with a covalent bond, using one electron from each carbon

  2. Attach hydrogen atoms to all other valence arms